This invention is generally directed to vehicle safety restraint systems including shoulder and lap-type seat belts and more particularly to such restraint systems which incorporate locking mechanisms for preventing release of latch plates from buckles of the restraint systems due to inertial forces created during vehicle accidents, such as in vehicle rollovers. The restraint systems can only be released by manually maneuvering mechanisms to consciously release the latch plates from the buckles of the restraint systems.
Body restraint systems including seat belts, lap belts, shoulder harnesses and the like have been credited with saving numerous lives which otherwise would have been lost in vehicular accidents. The positive benefits obtained in body restraints systems has been so recognized that in the United States the use of seat belts is mandated in all states.
Since their inception, there have been numerous innovative advances made to improve upon the safety and reliability of vehicle body restraint systems. Improvements have been made to the belt and belt materials, the manner in which the belt restraint systems are mounted within vehicles, the manner in which such restraint systems may be automatically adjusted to provide proper tension and ease of adjustment to suit not only safety standards but to also provide for a measure of passenger comfort and further to improve upon the security of the locking devices or belt buckles associated with such systems.
Most conventional vehicle body restraint systems incorporate a belt which either crosses in front of the lap or diagonally across the body of the vehicle operator or passenger in such a manner to not adversely interfere with the region of an individual""s neck. Belts are retained by latching assemblies including belt buckles into which latch plates carried by the belts can be inserted so as to automatically become locked to the buckles which are normally anchored relative to frames of vehicles. Conventional systems generally utilize two types of release mechanisms for allowing the latch plates to be removed from buckle housings such that drivers and passengers can disembark vehicles. A first or side release system includes an operating release button which is generally resiliently urged outwardly at an angle which is perpendicular to an axis or line of insertion of the latch plate into a buckle housing. A second type of conventional release system is known as an end release system wherein the operating lever or button for releasing the latch plate from the buckle housing is mounted at an end of the buckle housing.
Currently, virtually all types of latching mechanisms for body restraint systems in automotive vehicles are subject to premature release when subjected to at least one mode of inertial force which can be created under various conditions resulting from collisions, rollovers and other types of vehicle loss of control. Side release latching assemblies or mechanisms, such as referred to as Type 1 and Type 6 in the industry, will inertially release when subjected to lateral forces which are applied to a backside of a buckle during a vehicle collision or rollover. Such latching assemblies will also release by the release button being forceably engaged by an object in a vehicle accidently depressing the button during an accident, collision or rollover, thereby prematurely destroying the effectiveness of the restraint system which can cause severe or deadly injury to the person using the system.
End type release latching systems will inertially release due to the mass of the release buttons associated therewith when taken into consideration the mass of movement of the latch plate and the direction of rotational release of the latch plate when subjected to an upward or upward and lateral force opposite the locking direction of a latch dog associated with such a mechanism, especially during vehicle rollovers. This lateral mode of failure occurs when an occupant is more apt to be ejected from a vehicle and thus can result in severe bodily injury or death.
The above modes of failure are inherent in virtually all conventional side and end release latching mechanisms of conventional vehicle restraint systems. The side release buckle systems are generally simpler and have fewer moving parts and thus are more economical to construct and to install, whereas the end release systems are more complex having multiple moving parts and are thus more expensive to manufacture.
In view of the foregoing, there remains a need to further improve upon the reliability and effectiveness of vehicle body restraint safety belt systems to ensure that the latching mechanisms associated therewith cannot be accidently released during substantially any type of vehicular movement including vehicle rollovers caused during accidents, collisions or resulting from loss of control of a vehicle, such as by operator error or vehicle equipment failure. There is a further need to provide for improvements in vehicle body restraint systems which permit the latching assemblies to be more reliable and more economic to construct.
The present invention is directed to vehicle body restraint systems which include buckles for latching and restraining latch plates. Several preferred embodiments of the invention will be disclosed. The embodiments are designed to prevent inertial release of safety restraint buckle or latching assemblies associated with vehicles by requiring intentional manual rotation of release mechanisms associated with the buckles to allow release of latch plates associated with the safety belt restraint systems.
In the embodiments of the invention, each safety belt of each restraint system is provided with a latch plate which is insertable so as to be locked and retained within a buckle having internal latching components for engaging and preventing the removal of the latch plate until manually released. Each system includes a belt buckle housing having an opening therein in which the latch plate is slidably received. Mounted interiorly of the buckle housing is a movable locking component which is operable in a first position to engage within an opening in the latch plate to thereby prevent the withdrawal of the latch plate until the locking component is moved from such opening.
In a first embodiment of the invention, the locking component is a latch member which is moved by a latch screw having threads which engage with threads of an opening or hole in the latch member. The latch member is pivotable within a buckle housing and includes a latch dog which is engageable with an edge of the latch plate defining the opening in the latch plate to thereby prevent lateral shifting or withdrawal of the latch plate once it has been inserted within the buckle housing. The latch screw is operatively connected to a pivotal release mechanism such as a knob which can be manually rotated in order to cause pivotal movement of the latch member to release the latch dog from engagement with the latch plate thereby allowing removal or ejection of the latch plate from the buckle housing.
In the first embodiment, a torsion spring is mounted about the latch screw and is secured to the latch screw in such a manner as to supply or apply a constant rotational force to the latch screw in a first direction such that, upon insertion of the latch plate within the buckle housing, the latch member locking dog is urged into engagement with the latch plate as soon as the opening of the latch plate passes the latch dog of the latch member. In this embodiment, the rotational loading of the latch screw torsion spring is caused by manual rotation of a pivotal release member such as a knob which is connected to the latch screw. As the latch screw is rotated, the latch member is moved from the first xe2x80x9clockedxe2x80x9d position engaging the latch plate to a second xe2x80x9creleasexe2x80x9d position wherein the latch member is moved by the latch screw to permit release of the latch plate of the seat belt system. As the torsion spring is attached to the latch screw, the spring is wound and placed under torsional force as the knob is rotated to release the latch plate.
In the present embodiment, when the latch plate is inserted into the buckle housing, the latch plate will initially engage a locking and ejector mechanism which normally is in a first locking position wherein it retains the latch member in the second or xe2x80x9creleasexe2x80x9d position. As the latch plate is inserted further, the locking and ejector mechanism is moved free of the latch member and, when the latch plate is fully inserted into the buckle housing, the opening therein will pass the latch dog of the latch member thereby allowing the latch member to be moved by the force of the torsion spring such that the latch dog blocks the withdrawal of the latch plate from the buckle housing. As the latch screw is rotated by the torsion spring to urge the latch member into the first xe2x80x9clockedxe2x80x9d position, the release knob will be rotated such that a locking member on the lower portion of the knob will engage within a detent provided in an outer surface of the buckle housing thereby preventing further rotation of the latch screw. In some embodiments, the locking member associated with the knob or other pivotal member will be operative when the latch member is in either the first xe2x80x9clockedxe2x80x9d position or the second xe2x80x9creleasexe2x80x9d position.
In the present embodiment, resilient means are associated with the locking and ejector mechanism for automatically ejecting the latch plate upon release of the latch plate upon manually rotation the latch screw by operation of the release knob. The rotation of the release knob rotates the latch screw relative to the latch member thereby driving the latch member in a pivotal motion away from the opening in the latch plate and thereby releasing the latch plate. During this motion, a slide lock of the locking and ejector assembly will block the latch member and retain it in the xe2x80x9creleasexe2x80x9d position.
With the present embodiment, should the latch plate not be inserted fully into the housing, the ejection means, such as spring(s), will automatically eject the latch plate thus ensuring that an individual knows that an appropriate locking engagement has not been made. However, once the latch plate is inserted to a sufficient degree to allow the latch member dog to engage against the edge defining the opening in the latch plate, the locking member associated with the release knob engages in the detent or recess and will have sufficient retaining force to prevent rotation of the latch screw until the release knob is manually rotated releasing the locking member from the recess and rotating the latch screw to pivot the latch member away from the opening in the latch plate.
In another embodiment of the present invention, the latch plate is insertable within an opening in one end of the buckle housing and slides into a passageway of a size to cooperatively receive the latch plate. Extending transversely to the passageway within the buckle housing is a chamber which is defined preferably by linear side walls in which a latch member is slidably disposed. The latch member is movable from a first xe2x80x9clockedxe2x80x9d position in which the latch member is seated within an opening in the latch plate and thereby prevents release of the latch plate from the buckle housing, to a second position, wherein the latch member is moved free of the opening in the latch plate to thereby permit the automatic ejection of the latch plate. The latch plate is ejected by a resilient member and slide lock which are aligned with the latch plate and which are loaded to provide an ejecting force upon insertion of the latch plate into the buckle housing.
As with the previous embodiment, control of the movement of the latch member to release the latch plate is effected through the intentional manipulation of a pivotal control or release member such as a knob which is mounted on an exterior surface of the housing. The control knob or other pivotal member is operatively connected or secured to a latch screw which is threadingly engaged within an opening within the latch member such that by rotation of the latch screw, a sliding motion is established with respect to the latch member within the latch member chamber.
A torsion spring is mounted about a portion of the housing and has one end anchored thereto and a second end engaged with the release knob or other member such that a constant rotational force or torque is supplied to the latch screw. The latch member is normally retained in a second open or xe2x80x9creleasexe2x80x9d position by the slide lock which is engageable within an opening or slot in the latch member when the latch member is in the xe2x80x9creleasexe2x80x9d position. The slide lock is controlled by the resilient force of the ejection spring associated with the buckle assembly such that, upon insertion of the latch plate within the housing of the buckle, the slide lock is engaged by the tip of the latch plate and urged against the resilient ejection member, thereby moving the slide lock free of the latch member. When the slide lock disengages the latch member, the latch member is free to move axially, guided in a non-rotational movement by the side walls of the latch member chamber. The torsion spring applies a rotational force to the release knob or other pivotal member in a first direction thus creating a rotational force on the latch screw in a first direction and moving the latch member from the xe2x80x9creleasexe2x80x9d position to the xe2x80x9clockedxe2x80x9d position wherein the latch member is seated within the opening of the latch plate, thereby preventing withdrawal of the latch plate. The torsion spring continues to apply force urging the latch member into the locked position and thus prevents the release of the latch plate in the event of a vehicle rollover or any other type of vehicle movement which is generated by a collision or accident. The only way the latch plate can be released is by manually rotating the release knob or other pivotal member in a second counter direction thereby moving the latch member along a portion of the length of the latch screw and withdrawing the latch member from the opening in the latch plate. The latch member is moved until the opening therein aligns with the slide lock such that the slide lock seats in the opening and retains the latch member in the xe2x80x9creleasexe2x80x9d position. Simultaneously, the release spring will eject the latch plate from the buckle housing. From the foregoing, it can be seen that the torsion spring associated with the present embodiment is placed under force when the release knob or other pivotal member is manually rotated to release the latch plate thereby ensuring that appropriate force is supplied to automatically move the latch member to the xe2x80x9clockedxe2x80x9d position upon the reinsertion of the latch plate and release of the slide lock from the latch member.
In both the first and second embodiments, it is preferred for the torsion springs and the latch screws to be preloaded, in torque, such that the force against the latch members to urge the latch members to the first xe2x80x9clocked positionxe2x80x9d is in a direction such that any forward pitch of a vehicle adds to the torque thus further forcing the latch members to the xe2x80x9clockedxe2x80x9d position. Also, the pitch of the threads of the threaded components are such that any foreseeable lateral forces which may act on the safety belt restraint systems during accidents will not cause rotation of the components.
It is the primary object of the present invention to provide vehicle body restraint systems which incorporate latching buckles or assemblies which will not release due to inertial forces which may be encountered when a vehicle is in a collision or accident in which the vehicle may pitch or rollover or be otherwise moved and such that the release of the latch plate of the restraint system can only be accomplished by an intentional rotational movement of a pivotal release mechanism.
It is yet another object of the present invention to provide vehicle body restraint systems which incorporate buckle latching mechanisms or assemblies wherein ejection mechanisms are provided for ejecting the latch plates unless the latch plates have been inserted to a proper degree to positively lock the latch plates within the buckle housings.
It is yet a further object of the present invention to provide locking assemblies for use with vehicle body restraint systems which cannot be accidently engaged and released by objects or inertial forces during a collision or vehicular accident as is the case with the conventional push button-type locking assemblies.
It is also an object of the present invention to provide buckle and latch retaining elements for vehicle body restraint systems which can be economically manufactured and which can be safely used to prevent premature seat belt release in the event of vehicle collisions or other accidents.